The brother-in-law of Prince Charles has died after sustaining a serious head injury following a fall during a night out in Manhattan, British royal officials and local authorities said Wednesday.

Mark Shand, the brother of Camilla Parker Bowles, the Duchess of Cornwall, reportedly fell and struck his head on the ground just hours after he attended a charity auction at Sotheby's.

Shand fell outside of 2 Lexington Avenue shortly before 3 a.m. and was taken to Bellevue Hospital, according to first responders.

Camilla, her husband Prince Charles and all of her family members are "utterly devastated by this sudden and tragic loss," Clarence House said in a statement.

"Mark Shand was a man of extraordinary vitality, a tireless campaigner and conservationist whose incredible work through The Elephant Family and beyond remained his focus right up until his death," it said.

Shand was chairman of the elephant conservation charity and is known for his work as a travel writer and conservationist. He is the author of several books including "Elephant Tales" and "River Dog: A Journey Down the Brahmaputra."

He was in New York for a charity auction at Sotheby's. The auction house said Wednesday it was "deeply saddened" by the news, and that it was honored to have helped him raise money for his causes.